Patrick mcculpha



(No Model.)

P. MGCULPHA.

HOT AIR FURNAGE.

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PATRllCK MCCULPHA, OF NEV YORK, N. Y.

HOT-AIR FURNACE.

PEOIFICATON forming part of Letters Patent No. 359.73%, dated Max-cli 22, 1887,

Application filed September 24, 1886. Sci-inl Xo. 214,456. (No model.)

T0 all whom, it 77mg/ concern:

Be it known that I, PATRICK HCCULPHA, of the city, county, and State of New York, have invented a new and useful Improvement in Hot-Air Furnaces; and I do hereby declare thatthe following is a full and exact description thereof', reference being had to the accompanying drawings,and to the letters of reference marked thereon, making a part of this specification, in which- Figurel is a front elevation of my improved hot-air furnace; Fig. 2, a plan of same with the top removed, and Fig. 3 a vertical longitudinal section in line a: x of Fig. 2.

Similar letters of reference indicate like parts in each of -the figures.

My invention relates to that class of furnaces which are constructed with hot-air tubes,each ot' which passes independently through the combustion-chamber,and from thence directly to the apartment to be heated.

It has for its object to simplify the construction of the furnace and increase its efficiency for delivering large volumes of pure, fresh, warm air into the building and equally under all conditions to each of therooins tobeheated V screwed directly into holes tapped in the side and Ventilated.

It consists in the combination of a U -shaped air-supply chamber formed of pipes extending in a rectangle around three sides ofthe upper part ofthe combustion-chamber of the furnace,and whose two ends both open directly into the outer air, with a series of small delivery-pipes fitted into the transverse arm of lche supplychanibe1,to extend thence independently horizontally or with a slight upward inclination entirely across the furnace, each to connect with a separate conductingtube leading to one of the apartments in the buildinff.

Iprefer to construct the outer walls, A A A', of my furnace of brick in a rectangular form, either square or oblong, the pipes in thelatter case being fitted to extend lengthwise thereof. At the front end of the furnace I form a fire pot or chamber, B, fitted with a grate, C, of any approved construction over a suitable ash-pit, D. rthis fire-pot is lined with firebriclt in the customary manner. It is made much smaller than the body of the furnace and the space at the sides and rear thereof are preferably filled in,to retain the heat imparted thereto, insure a more uniform and constant temperature, and facilitate the maintenance of the fire after the furnace has been put into operation.

In the upper part of the chamber E, which is incloscd by the outer walls, A A A', of the furnace, three large Wrought-iron gas-pipes, F F F', are fitted and united by means of the elbows G G, to form a U-shaped or rect-angular air-supply chamber, and are supported Within the upper portion of the chamber E near to the Walls thereof, as shown in Flo". 2. The two lateral pipes F F" of this U-shaped chamber are made to extend out through the rear Wall, A', of the furnace with. a close joint, and are preferably both continued through the outer wall, lV, of the building, so as to open directly into the fresh outer air.

The front transverse section or pipe, F, of the supply-chamber is mounted directly over the fire pot or chamber B. To this front section, F, the delivery-pipes H H H are connected. These delivery-pipes are preferably formed of Wrought iron tubes, which are ofthe section F, and which, extending thence across the furnace from front to rear in lines parallel with each other and with the side pipes, F F', project, each with a tight joint, through its rear wall, A', and are fitted with elbows to receive each a separate conductingtube, It, leading to some one of the several apartments to be heated.

By observing a due proportion between the size ofthe pipes F F' F', forming the U shaped air-supply chamber, and of the separate delivery-pipes H H H, extending thence out from the furnace, with reference to each other and to the sizeof the fire-potand furnace, as many pipes may be used as there are rooms to be heated, so that each shall receive a constant and independent supply of pure hot air.

The rear wall of the fire-pot B is carried up entirely across the furnace-chamber nearly to the under side ofthe delivery-pipes H H, so as to form a bridge-wall, which will carry the flames and products of combustion directly up against the pipes. The chimney or discharge- ICO flue K for the furnace is located centrally at its rear end, se as to cause the hot gases to sweep along, over, and between the tubes H H.

The top of the furnace may be arched over or be closed, as shown in the drawings, by an iron plate, S, upon which an outer lining of brick, T, is placed.

In the operation of the furnace the outer air entering the two lateral pipes F F flows in through these pipes toward their central. conneetingpipe, F, and the air in passing through these lateral pipes is measurably heated before it reaches the central pipe. In this central pipe, F, it is subjected more directly to the heat of the fire, and expanding therein creates an outward pressure in the deliverypipes A H II, which open into it, and thus a strong current is formed in each of said pipes, the inward flow in opposite directions from the two lateral pipes F F at each end of the connecting-pipe F serving to insure a constant, uniform,and equablesupplyto each delivery-pipe. The delivery-pipes H II are subjected to the full heat of the fire throughout their length, and the heated air flowing through them from the front pipe, F, becomes rapidly hotter and passes out through the conducting-tubes R R into each apartment at a suitable temperature to heat the same, and in such volume and under such conditions as respects freshness and purity as to insure the healthfulness thereof. The rapidityof the flow of the air prevents it from losing its vitality by deoXygenat-ion in contact with the hot pipes and prevents the latter from overheating, while the simplearrangement of the air-conducting pipes coupled by `threaded joints prevents the possibility of any leakage of gas thereinto from the combustion-chamber.

The furnace is constructed at a compara.` tively low cost, and its economy of fuel `and efficiency,l as proven by practical tests, render it superior to the cast-iron furnaces in general use.

I am aware that a hot-air furnace has here tofore been constructed with one or more independent hot-ai r pipes extending directly through the furnace, opening outwardly on one side to receive the air and connected at the other, each to a conducting-tube leading to an apartmentv to be heated; but where the hot-air pipes are thus lcd directly thronghithe furnace, eachhaving an independent external connection with a cold-air supply, the passage of the cold air istoo rapid to insure proper heating, and the furnace is not effective or economical. By my invention I insure the requisite freedom of flow and constancy and adequacy of supplyy neededto afford good ventilation, and. at the same time obtain, with econ only of fueha proper elevation oftemperature by the combination of the large U -shaped airchamber consisting of airsupply pipes in the `form of a rectangle placed within the fui nace, but opening freely at both ends into the; outer air, with a series of independent deliverypipes, each eonnectediwithin the furnacei to the transverse arm `of ther U-shaped openended chamber, and arranged to extend thence across the hottest part of the furnace before passing out to the several apartments which they are designed to supply.

I am also aware that grates havelbeen constructed with hollow grate-bars opening into the apartment to be heated and connected with upright ilues at therear, extending for-y ward above the grate to open falso into the same apartment, whereby a circulation of air is produced from the apartment through the grate-bars and flues back into it lagain, provision being made for an admission of fresh air, if desired, into said fines; but this system differs from my invention in that `the lower flues or hollow grate-bars are covered by the ashes and cinders under theincandescent fuel in the grate, and that the upper flues `are eX- posed to the drafts or cold air `entering the grate over the lire, sothatsaid system of fines, while useful as an auxiliary to an open grate in heating a single apartment in which it is placed and in producing a circulation of warm air in the apartment, is whollyunsuited and inoperative for the purposes of a furnace in heating a number of separate apartments,and my invention differs fromthese grates, not only in the arrangement` and combination of i the heatingtubes with the furnace, as hereini before described, but also in the results attained by said arrangement and combination.

I claim as myinventionw IOO The combination, with the fire-pot and heatingchamher, in a iurnace,of a rectangular or U-shapedair-supply chamber, mountedin i the upper portion ofthe heating-chamber,with its transverse arm or bend over the dre-pot and its lateral arms extending horizontally along the sides of the chamber, botluopening freely outwardly to receive a fresh-air supply, a series of parallel delivery-tubes connected to said transverse arm to open freely thereinto,and extending thence each independently through the upper portion of the heating chamber from front to rear between said lat eral arms, and separate conductingfiueseach communicating with one of said delivery-tubes, 1 and `extending thence toionei of the several apartments to be heated, all substantially in the manner and for the purpose herein set forth.

In testimony whereofI have signedmyname to this specification in ythe .presence of two subscribing witnesses.

PATRICK .MCCULPHAW vit-messes:

S. A. Sravnns, A. N. Jnsennn.

IIO 

